<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>map</title>
</head>
<body>
	
</body>
</html>
<script src="../2.1.8/vue.js"></script>
<script>
	/*
		返回一个新对象
	*/
	var str = '159753';
	var arr = [...str];
	var newArr = arr.map(function( item ){
		return item + 2;
	});
	console.log( newArr,arr );
</script>